Improvement in retorts for distilling oils from coal



Patented Jany 11, 1.859.

We g@- J.. OHARA,

Oil Stili.

llrvrrnn Stratrns Parietti* @risica JAMES OHARA, OF PITISBURG, PENNSYLVANIA.

IMPROVEMENT EN RETORTS FOR DISTlLLlNG (NLS FROM COAL..

Specification forming part of Letters Patent No. 222,573, dated January l1, i559.

To @ZZ whom it may concern.-

Be it known that I, JAMES OHARA, of Pittsburg, in the county of Allegheny and State of Pennsylvania,have invented a new and useful Improvement in Retorts for Distill ing Coal in the Manufacture of Oils; and I do hereby declare that the following is a full,

y clear, and exact description of the same, ret'- crence being had to the accompanying drawing, forming part of this specification, said drawing representing a central vertical section of a retort with my invention applied.

rI`his invention consists in the employment within an upright retort for distilling coal in the manufacture of coal -oil of an upright screw of a smaller circumference than the interior of such retort, arranged with its axis in or nearly in the center thereof, and having imparted to it a rotary motion in such a direction as to cause the continuous elevation of the central portion of the charge of coal, which elevation is necessarily accompanied by the continuous descent of the exterior por tion by gravitation, and consequently a positive continuous and uninterrupted circulavunderstand my invention, I will describe its construction and operation.

A is the' retort, of iron, nre-clay, or other substance,having cylindrical sides, and its top and bottom convex, or of other form. This retort is intended to be heated by any of the methods generally employed for heating such retorts, and to be furnished with a door at the top for charging it with coal, and one at the bottom for discharging the coke, and with a pipe at the top for conveying the vapors of distillation to the condenser.

B is the revolving screw for producing the circulation in the retort, having one or more threads, and being made as small as possible at its center, so as to give it the greatest practicable depth of thread in proportion to its external circumference, which should be such as to encircle an area equal to about half the horizontal area of the retort. This screw is l attached to a shaft, C, which passes through the top of the retort, and is fitted to and supported by bearings in a suitable frame-work erected above, and it may or may not have a bearing in the bottom of the retort. The opening in the top of the retort where the said shaft C passes through should be luted. The said shaft may be driven by any convenient means to produce a continuous revolving motion of the screw, the velocity oi' which should be such as to keep up an active circulation-say thirty (30) revolutions per minute; but such velocity may be varied very materially.

In the particular examplev of my invention represented the screw has a right -handed thread, and consequently rotates in the direction ot' the arrow shown on the shaft to produce Vthe elevationfofvth/e coahwhich occupies the central portion of the retort between its threads. It is obvious that the continuous elevation of the central portion of the charge ot' coal would leave an empty space at the center of the bottom of the retort, but that the coal occupying the portion of the retort outside of the screw descends continually by gravitation to fill said space. rIhe coal, as it is caused by the action of the screw to arrive at the surface, falls toward the sides of the retort to till the space left by the descending portion; and hence it will be readily seen that a continuous circulation of a positive character turn be brought to the hottest part of the retort, which, when the usual methods of heating are employed, is generally at or near the bottom. v

Ihe screw may be surrounded by a stationary cylinder, which iits it closely, but which extends neither to the top nor bottom of the retort, but permits the passage ofthe coal under and over it. The cylinder will cause a more perfect and positive upward and downward circulation; but it is liable to objection on account of the friction produced between it and the screw.

I do not claim, generally, the use of a stirring apparatus within a retort, as I am aware that such apparatus has been used in retorts for some distilling processes; but

That I claim as my invention, and desire to secure by Letters Patent, is

The employment,in an upright retort for is kept up, and every part of coal Inust in its distilling coal, of a revolving screw of a cira positive continuous and uninterrupted upcumference smaller than the interior 4of -the Ward and downward circulation7 substantially 1etort,'so applied that While by its revolution as and for the purpose herein set forth.

it produces a continuous elevation of the cen- JAS. OHARA. tral portion of the charge it permits and fitnesses:

causes a continuous descent of the surround- AND. MoMAsTER,

ing portion by gravitation, and thus produces G. M. l\ICl\IAsT1R.l 

